水下平台对卫星上行激光通信研究

在合理选择通信系统参量和通信信道参量的基础上,利用Monte Carlo方法模拟了卫星接收到的水下平台上行激光通信信号.分析了卫星接收信号的空间和时间分布特性,以及与望远镜接收视场角的关系,并计算了接收信号的信噪比,得出了3°望远镜视场角和15 μs信号积分时间的优化参量.基于计算结果,根据激光脉冲的PPM调制方式和最大似然检测方法,计算了系统的通信误码率,同时分析了海气界面、云等传输介质对通信的影响.研究结果表明:根据文中给定通信系统参量,在典型海水、海气界面、云等环境条件下,卫星与激光信号中心水平距离5 km范围内信号误码率<10－4.因此位于水下60 m的水下平台可能实现对卫星上行激光通信.

Uplink Laser Communications Between a Satellite and a Submerged Platform

The uplink laser communication signal from a submerged platform to a satellite is simulated using Monte Carlo method with certain communication system parameters and reasonable channel parameters.The temporal and spatial distributions of received signal and the relations between signal and telescope′s field of view are analyzed.The signal to noise ratio of the receiver is calculated,which educes the optimized field of view of 3° and sample time slot of 15 μs.Then the error probability of the communication system is computed for laser pulse position modulation (PPM) and maximum likelihood detection.The results show that the error probability is below 10－4 when horizontal distance from satellite to laser signal center is less than 5 km.Consequently,the uplink laser communication between a submerged platform at 60 m depth and a satellite can be achieved under slightly severe environment.